• 한국자동차공학회논문집
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• 제2권6호
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• pp.9-17
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• 1994

In this study, a shifting algorithm of CVT was suggested for the two(2) driving modes : (1) power mode and (2) economy mode. Shifting algorithm must be obtained to make the engine run on the optimum operating line for the desired performance of the vehicle. Optimum operating lines of the engine were obtained by connecting the shortest way of the iso-power lines for the power mode and by connecting the shortest way of the BSFC curves for the economy mode. Also dynamic model of CVT vehicle was derived considering the throttle and the brake operation. By using the shifting algorithm and the CVT vehicle model, numerical simulations were performed to estimate the performance of CVT. Simulation results showed that comparing the performance of the conventional 4-speed automatic transmission, acceleration performance of the CVT vehicle was almost same with the AT vehicle for the power mode and the fuel economy of CVT was 14% superior than that of AT for the economy mode.

• 한국자동차공학회논문집
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• 제3권2호
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• pp.1-15
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• 1995

The driving patterns in Seoul metropolitan area were surveyed in an experiment involving 1,212km of driving along seventeen representative routes. The speed and fuel consumption data were recorded and the influence of driving patterns on vehicle fuel economy was analyzed by statistical techniques. The results showed that characteristics of driving in Seoul metropolitan area are far different from that of CVS-75 mode and then on-road fuel economy in Seoul may be small as compared with that of CVS-75 mode. Finally, it was proposed that CVS-75 mode fuel economy should be modified by applying adjustment factor to represent actual on-road fuel economy.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.104-104
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• 2011

The fuel economy estimates essentially serve two purposes : to provide consumers with a basis on which to compare the fuel economy of different vehicles, and to provide consumers with a reasonable estimate of the range of fuel economy they can expect to achieve. The current fuel economy label values utilize measured fuel economy over city driving cycles. However, this test driving mode can not be evaluated the variety factor of the real-world. These factors include differences between the way vehicles are driven on the road and over the test cycles, air conditioning use, widely varying ambient temperature and humidity, widely varying trip lengths, wind, precipitation, rough road conditions, hills, etc. The purpose of this paper is to account for three of these factors on the fuel economy : 1) on-road driving patterns (i.e. higher speeds and more aggressive driving (higher acceleration rates)), 2) air conditioning, and 3) colder temperatures. The new test methods will bring into the fuel economy estimates the test results from the five emissions tests in place today : CVS-75, HWFET, US06, SC03 and Cold CVS-75. Based on these new test methods, this paper discusses the characteristics of driving condition on Hybrid electric vehicle (HEV). And this paper assesses the fuel economy label of HEV.

• 동력기계공학회지
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• 제21권4호
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• pp.57-61
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• 2017

The vehicle label fuel economy is used as an energy management indicator nationwide. It induces technology development of automobile manufacturers and plays a role of providing information when purchasing a consumer vehicle. However, consumers who purchase a new vehicle continued to complain that the label fuel economy is different from the mandatory fuel economy rate. The domestic fuel economy measurement method is the same as the North American measurement method. The results of the two test modes (urban (FTP-75 mode), highway (HWFET mode)) are calculated in five test modes reflecting various environmental conditions and driving patterns 5-cycle correction formula is used which is equivalent to the fuel efficiency value. In this study, to solve the consumers' curiosity about the fuel economy of new vehicle, we use domestic fuel economy measurement method to measure the new car condition within 150 km of driving distance and the cumulative driving distance condition of domestic label fuel economy test vehicle. A comparative evaluation of fuel economy was carried out for a durability vehicle of $6,500{\pm}1,000km$. A result, mean value of the fuel economy of the four gasoline vehicles increased by 2.7 % in the city center mode and by 2.5 % in the highway mode in the durable vehicle compared new vehicle. And in the case of the diesel vehicle it increased by 2.5 % and 3.9 % respectively. The harmful exhaust gas emitted from the vehicle also resulted in more emissions of both gasoline and diesel vehicles in new vehicles. It is considered that the increase of the frictional force of the vehicle driving system and the lubricating oil system would have an effect on the reduction of the fuel economy of the new vehicle, and it was found that the fuel economy and the exhaust gas were improved by proper cumulative distance (domesticate) to the new vehicle.

• 에너지공학
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• 제25권4호
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• pp.198-206
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• 2016

자동차 표시연비는 국가적으로 에너지관리 지표로서 활용되며, 자동차 제작사의 기술개발을 유도하고, 소비자 차량구매 시 정보제공의 역할을 담당하고 있다. 하지만 정부의 표시연비가 체감연비와 상이하다는 소비자 불만이 지속되어 정부는 보다 정확한 표시연비 측정을 위해 미국의 5-cycle 시험방법을 국내 차량 기준에 맞게 재설정하여 도입하였다. 본래는 다양한 환경조건 및 주행패턴이 반영된 5개의 시험모드를 모두 주행함으로써 측정된 결과 값을 표시연비로 계산하는 방법이지만 소요되는 자원의 급격한 증가에 따른 충격을 완화하기 위하여 2개의 시험모드(도심(FTP-75 mode), 고속도로(HWFET mode))의 결과 값을 5-cycle 시험법으로 계산된 연비 값과 동등한 수준으로 산출하는 5-cycle 보정식을 사용하고 있다. 이 보정식은 2011년에 30대 차량의 5-cycle 시험방법으로 산출되었으나 최근 자동차 기술의 급속한 발전으로 인한 신형식 자동차에 대한 기존 5-cycle 보정식에 대한 검토가 필요할 것으로 판단되었다. 본 연구에서는 최근 기술이 적용된 14대의 신형식 자동차를 대상으로 기존과 동일한 시험 방법을 통해 시험모드별 연비 특성을 확인하고, 기존에 개발된 보정식과 차이를 분석한 결과 기존 시험 차량 결과와 큰 차이를 보이지 않았으며 보정식 또한 최대 1.5% 이내의 오차로써 기존 연비 보정식은 현재의 자동차 기술발전에 따른 개선도에 크게 영향을 받고 있지 않음을 알 수 있었다.

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.25-29
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• 2013

The purpose of this paper is to determine the fuel change and weight change impact on the fuel economy and emission characteristic of ICE (Internal Combustion Engine) vehicle. According to fuel type, fuel consumption and emission characteristics were measured and fuel used in this paper was gasoline, diesel, and LPG. Four vehicles with different weight were tested and the fuel economy were compared and analyzed by using scatter graph. Test was carried out using chassis dynamometer, CVS (Constant Volume Sampler), and emission measurement system. Diesel vehicle less emited $CO_2$ compared to gasoline and LPG. Even if same $CO_2$ between gasoline and LPG, there are difference fuel economy depending on carbon proportion of specific fuel. The heavier weight of vehicle, the worse of fuel economy and Better fuel economy performance on highway driving mode.

• 한국수소및신에너지학회논문집
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• 제29권6호
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• pp.661-667
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• 2018

Electric vehicles are taken a long time to charge and are restricted driving where charging infrastructure was not sufficiently constructed. The vehicle developed to solve these problems is a plug-in hybrid vehicle. It is possible to drive a certain distance by using electric motor and when the battery runs out, it operate the engine. Plug-in hybrid vehicle have a complicated structure and a lot of parts comparing a general vehicle because the electric parts and the internal combustion engine are installed together. Therefore, as the aging (mileage) of the plug-in hybrid vehicle, the influence which change of fuel consumption is expected to be larger than a general vehicle, but an experimental data are lacking. In this paper, we cumulate a mileage of the plug-in hybrid vehicle about 15,000 km and measured the fuel economy when the cumulated distance reached within 160 km, 6,500 km, 15,000 km respectively, by using domestic public test method. For measuring fuel economy of the vehicle, CD mode (driving distance on a single charge) which use only motor and the CS mode which operate motor and combustion engine were measured respectively. As a result, the fuel economy slightly increased at cumulated mileage of 6,500 km compared to the 160 km and the fuel economy of 15,000 km was similar to 160 km.

• 한국산학기술학회논문지
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• 제12권10호
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• pp.4283-4287
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• 2011

본 논문은 현재 출시되어 있는 소프트타입의 현대 아반테 하이브리드자동차와 하드타입 방식의 도요다 프리우스 자동차를 대상으로 차대 동력계상에서 CVS-75 모드를 주행하면서 발생하는 배출가스특성과 연비특성을 실험적으로 분석하였다. 가솔린 차량에 비해 하이브리드 차량의 연비 및 배출가스 특성이 탁월하였으며 특히, 하드타입의 하이브리드 차량이 소프트타입의 차량에 비해 연비개선효과가 우수하게 나타났다.

• 융복합기술연구소 논문집
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• 제5권1호
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• pp.23-26
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• 2015

The purpose of present study is to analysis the Characteristics of fuel economy and Green house gases due to the driving mode conditions of The hybrid electric vehicle(HEV). HEVs are divided into mild and power types according to the their functions. mild type HEVs are inexpensive because they do not need to implement a pure electric mode. Power type HEVs are more expensive but has also better fuel efficiency. In the present paper, the test results for the gasoline vehicle using FTP-75 mode and HWFET are present.

• 대한기계학회논문집
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• 제18권11호
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• pp.2817-2824
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• 1994

A torque split type multi-pass CVT(MPC) system consiting of CVT and planetary gear train with 4 clutches was suggested to overcome the inherent inferior acceleration performance of CVT. Also, a shifting algorithm of MPC was suggested for the two driving modes : (1) power mode and (2) economy mode. By using the shifting algorithm and the MPC vehicle dynamic model, numerical simulations were performed to estimate the performance of the MPC vehicle. Simulation results showed that comparing the performance of the conventional 4-speed automatic transmission, an improvement in acceleration can be obtained by MPC for the power mode and 31% improvement in fuel economy for the economy mode.